Abstract:Objective To evaluate the potential diagnostic value of neutrophil/lymphocyte ratio (NLR) in preeclampsia. Methods We searched PubMed, Embase, Cochrane Library, the Chinese National Knowledge Infrastructure (CNKI) databases, Wanfang data, VIP database and China biomedical literature database systematically for relevant literatures up to May 20, 2018. All analyses were conducted using Meta-DiSc 1.4 and Stata 12.0 software. Sensitivity, specificity and other measures of accuracy of NLR for the diagnosis of pre-eclampsia were pooled. Meta-regression was performed to identify the sources of heterogeneity. Results This meta-analysis included a total of 7 studies. The overall sensitivity and specificity were 0.74 (95% CI: 0.71, 0.76) and 0.64 (95% CI: 0.61, 0.68); positive likelihood ratio was 1.96 (95% CI: 1.79, 2.16), and negative likelihood ratio was 0.43 (95% CI: 0.38, 0.47); diagnostic odds ratio was 4.68 (95% CI: 3.93, 5.58); and area under the curve was 0.82. Meta-regression showed that sample size was the main source of heterogeneity. There was no statistical significance for the evaluation of publication bias (P?>?0.05). Conclusions Current evidence suggests that the diagnostic accuracy of NLR has unsatisfactory specificity but acceptable sensitivity for diagnosis of preeclampsia. Further large-scale prospective studies are required to validate the potential applicability of using NLR alone or combination with other markers as preeclampsia diagnostic biomarker.